1. Field of the Invention
The present invention relates to a device which checks the shape of a nozzle tip of a laser beam machine for any abnormality (foreign matter, deformation, or tip flaws) using a shape/property recognition device such as a camera.
2. Description of the Related Art
In the case of conventional laser beam machines, predetermined standard machining conditions are registered with an NC system according to material and workpiece thickness.
When laser machining is continued under standard machining conditions, abnormalities of the nozzle attached to the tip of the machining torch can cause machining defects such as generation of dross. To maintain optimum machining conditions, conventionally the operator has to sense anything unusual in advance, stop the machine, check the nozzle, and if any abnormality is recognized, the operator has to replace the nozzle manually, clean the nozzle, correct any deformation, or change machining conditions.
A device is known which can detect any machining defect of workpieces by carrying out imaging of cut portions of the workpieces with a CCD camera (Japanese Patent Laid-Open No. 10-258376, or Patent Document 1).
Any foreign matter attached to the nozzle of the laser beam machine makes it difficult to maintain a fixed clearance between the tip of the nozzle and top face of the workpiece in a stable manner. This will cause machining defects such as degradation of machining quality or even disable machining.
Also, any foreign matter attached to the nozzle tip can cause an outlet in the nozzle tip to go out of round, disturbing flow velocity distribution of jets of assist gas. This will cause machining defects such as degradation of machining quality or even disable machining.
To avoid the above problems and maintain optimum machining is something an unskilled operator cannot accomplish and requires a skilled operator with many years of experience. This has hindered continuous unattended operation from being implemented.